AU2007100606B4

AU2007100606B4 - Liquid tanks

Info

Publication number: AU2007100606B4
Application number: AU2007100606A
Authority: AU
Inventors: Mark Nicholas Collymore
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-07-04
Filing date: 2007-07-04
Publication date: 2007-08-16
Anticipated expiration: 2015-07-04
Also published as: AU2007100606A4

Description

P/00/012 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: "LIQUID TANKS" The following statement is a full description of this invention, including the best method of performing it known to me/us: LIQUID TANKS This invention relates to liquid tanks especially for storing liquids inclusive of water.

Reference may be made to US Patent 6,739,469 which refers to water tanks having a cylindrical shape and made from arcuate steel panels bolted together having a cone shaped bottom and cone shaped top. There is also provided reinforcing elements located on each side of connection portions of adjacent arcuate steel panels as well as radially oriented reinforcing bars at the top and bottom of the tank.

Reference also may be made to US Patent 5,474,207 which describes a rectangular liquid storage tank having outer walls made up of square panels bolted together and a plurality of non metal tie rods extending across an interior of the tank to prevent outward bulging of the tank walls. The non metal tie rods have corrosion resistant bolts at each end which have a hollow bore with the tie rods adhesively secured therein. The bolts have turnbuckle means for tensioning the tie rods.

Reference may also be made to International Publication 2004/056677 which refers to a prefabricated water tank formed from coupling a plurality of bottom panels, side panels and top panels with each other while interposing sealing members between adjacent flanges of adjoining panels. Each of the panels is made of metal. There is also provided an inner reinforcement section installed in the tank interior to endure against internal hydraulic pressure and an external reinforcement section located outwardly of the tank also to endure against internal hydraulic pressure. The 2 internal reinforcement section includes horizontal reinforcement bars interconnecting adjacent outer walls of the tank.

Reference may also be made to US Patents 4,350,258, 4,059,529, 4,789,170 and 5,421,478 which all describe tanks having internal baffles.

The foregoing prior art is typical of reinforced liquid tanks made from panels which have various problems including complicated reinforcement structure and high manufacturing costs. An example of complicated reinforcing structure is the tie rods and associated bolts discussed above in relation to US Patent 5,474,207.

To overcome these problems domestic water tanks are now manufactured principally from polyethylene. For example, such tanks may be installed on a concrete base or slab. The tanks have a gate valve and an access conduit and are cylindrical being provided with circumferential reinforcing grooves. Such tanks may be viewed at www.bundypolyind.com.au. These tanks are made from a rotational moulding process.

Reference also may be made to conventional water tanks made from polyethylene and in one particular example reference may be made to a water tank displayed at www.irrigationwarehouse.com.au which is a SLIMLINE T500 tank having a plurality of external corrugations or grooves located in a continuous side wall of the tank which has planar sides and arcuate ends. There is also provided a plurality of open ended internal bores or passages which have a progressively increasing taper or lateral dimension from one end to another. These tanks are also formed from a rotational moulding process.

However one disadvantage of polyethylene tanks such as the T500 referred to above was that the open ended internal bores discussed above were necessary reinforcing structure for the tanks and this increased manufacturing costs as well as decreasing the effective internal volume of the tank.

It also had to be borne in mind that tanks of relatively large capacity, e.g. 2500 to 5000 litres were expensive and were heavy and thus sometimes require 2 to 3 installers to carry such tanks for installation purposes. Also access to such tanks was relatively difficult after installation.

Also it was often the case that the required storage capacity of a storage system exceeds the capacity of any single tank which can be efficiently moved to the installation site.

To overcome these problems reference may be made to US Patent 6,491,054 which describes a modular tank system of a plurality of modular tanks which may abut each other or be spaced from each other and interconnected by a rigid pipe or semi-flexible hose. A coupling between the pipe and the tank incorporates a fitting, integrally moulded into the tank and a flexible sleeve which is clamped to and fits over the fitting and pipe. This enables the effective volume of the tanks to be greatly increased especially if water gains access to each of the tanks through an access opening located in the top wall of each tank. Each of the tanks may be provided with an upper and lower internal coupling.

It was also the case in US Patent 6,491,454 that each tank was of a specific shape for reinforcement purposes having alternating circular and octagonal ribs in a main body and curved, ribbed end caps. This increased the cost of manufacture.

US Patent 4,961,670 describes a modular tank system of abutting tank modules interconnected by fluid couplings. However in this reference it was necessary to utilise tank modules of a specific shape and structure having an upper wall part which is of parabolic arch shape and a base wall which was substantially flat. This arrangement is especially designed for septic tanks.

In summary of the prior art therefore it is evident that modular tank systems interconnected by flow conduits are already known to increase effective storage capacity when compared to a single tank. However such conventional modular tank systems used modular tanks of a special reinforced nature which increased cost of manufacture.

It is therefore an object of the invention to provide a modular tank system for storage of rainwater using corrugated tanks.

Therefore in one aspect the invention provides a modular tank system for storage of rainwater including a plurality of modular corrugated tanks each having a maximum capacity of 2500 litres having a lower flow conduit assembly connecting each of the corrugated tanks wherein said lower flow conduit assembly is attached to an adjoining modular tank by a coupling having a pair of seals formed from elastomeric material and having a peripheral shape that is complementary to corrugations of said adjoining tank wherein one of said seals abuts an internal surface of said adjoining tank bs Sand another of said seals abuts an external surface of said adjoining tank.

o Each of the corrugated tanks are preferably cuboidal having two pairs of mutually opposed side walls. Alternatively each tank has a pair of opposed planar or flat side walls or surfaces so that they can be installed with such flat surfaces abutting or flush with each other.

SThe modular tank assembly may also have an upper flow conduit assembly interconnecting each adjacent modular tank which increases the rate of filling each modular tank with rainwater.

The coupling may also include a screw threaded fitting which is screw threadedly attached to an adjacent flow conduit of the lower flow conduit assembly and which is also screw threadedly attached to a nut located on an internal surface of an adjacent tank.

Each lower flow conduit assembly may also include a flow valve assembly which may be of any suitable type such as a gate valve, spool valve, ball valve or any valve having a movable valve member movable by a handle for shutting off flow of water through the lower flow conduit assembly.

At least one of the modular tanks may be connected to a stormwater conduit which is in flow communication with a gutter or other receptacle for collection of rainwater.

b Reference may now be made to a preferred embodiment of the c invention as shown in the attached drawings wherein: FIG 1 is a perspective view of a modular tank system of the invention having two tanks interconnected by a bottom flow conduit and an upper flow conduit; OFIG 2 is a similar view to FIG 1 showing three tanks interconnected by 0a bottom flow conduit and an upper flow conduit; FIG 3 is a perspective view of two adjacent tanks showing the upper interconnection means between adjacent tanks and also showing a pair of inlet pipe sockets for incorporation of an adjacent bottom flow conduit; FIG 4 is a detailed view of the gate valve assembly used in the bottom flow conduit as well as the access assembly for attachment of an adjacent flow conduit; and FIG 5 is a perspective view of a top wall of a modular flow tank connected to an adjacent storm water drain.

In the drawings in FIG 1 reference is made to a modular tank assembly 10 of the invention having a pair of modular tanks 11 and 12 interconnected by an upper flow conduit assembly 13 and a lower flow conduit assembly 14. Lower flow conduit assembly 14 includes a pair of flow conduits 15 and 16 interconnected by gate valve assembly 17. Each of flow conduits 15 and 16 are attached to respective tanks 11 and 12 by access assemblies 18 and 19.

A similar arrangement is shown in FIG 2 which shows three modular tanks 20, 21 and 22 interconnected by upper flow conduit assemblies 13A and 13B and lower flow conduit assembly 14B. Lower flow conduit assembly 14B includes gate valve assemblies 17A and 17B, and end flow conduits 23 and 24 and intermediate flow conduit 25. Each of flow conduits 23 and 24 are connected to tank access assemblies 26 and 27 and intermediate conduit 25 has pipe 28 in flow communication with tank access assembly 29.

As shown in FIG 3 upper flow conduit assembly 13 may include a screw threaded pipe spigot 30 bonded or attached to tank 11 by elastomeric or rubber socket 31 which engages with a flange nut 32 having a flange 33 and nut component 34. As shown pipe spigot 30 extends through access aperture 35 of tank 12 and is retained in position by thread 36 of flange nut 32 engaging with mating screw thread 37 of pipe spigot In relation to the lower flow conduit assembly 14, this also includes pipe spigot 38 of tank 11 and pipe spigot 39 of tank 12 which screw threadedly engage with conduits 15 and 16 as shown in FIG 1.

In FIG 4 reference is made to access fitting 29 which has a screw threaded fitting 45 having flange nut 32 and screw threaded ends 47 and 49.

There is also provided a pair of sockets 31A and 31 B which are located on each side of aperture 44 of corrugated wall 46 of tank 21 and it will be noted that fitting 45 has flange nut 32 attached thereto wherein screw threaded portion 47 engages with inner socket 31 B and nut 48 and screw threaded portion 49 engages with an internal screw threaded socket (not shown) of flanged component 47 having conduit 50 and flange 51. It will also be noted that corrugations 40 have hills or ribs 41 and valleys 42. Each socket 31A and 31 B has a peripheral shape 32 that is complementary to corrugated wall 46 and this facilitates effective sealing action of sockets 31A and 31B.

The operation of an adjacent gate valve assembly 17B is also shown wherein reference is made to a rotatable handle 52, stem 53 for handle 52, ball 54 attached or integral with stem 53 and flow passage 55 which when in an open position permitting fluid flow is in registry with an internal passage (not shown) of flow conduit 25. Gate valve assembly 17B is screw threadedly attached to a mating internal surface (not shown) of each of end fittings 56 and 57 having tubular component 58 and flange 59.

Reference may also be made to FIG 5 showing tank 60 having a corrugated side wall 46 and top wall 61 having downpipe 59 which communicates with a gutter (not shown) or gulley trap or other component which collects rain which may have a surface run off into downpipe 59 which engages with elbow 62 and couplings 63 as shown. Access opening 64 is provided with filter or sieve In operation each of modular tanks 11 and 12 or 20, 21 and 22 are connected to each other by upper flow conduit assemblies 13 and 14 as shown in FIG 1 or upper flow conduit assemblies 13A and 13B and 14B as shown in FIG 2. When rain falls it is collected in downpipe 59 and passed into an adjacent modular tank 11 or 20 for example as shown in FIG 5 and the water is passed into adjacent modular tanks through lower flow conduit assemblies 14 or 14B as well as upper flow conduit assemblies 13 or 13A and 13B which provides a levelling effect between adjacent modular tanks 11 and 12 or 20, 21 and 22. It will be appreciated that additional rnodular tanks may be incorporated in the modular tank system of the invention so as to increase internal capacity of the system. The gate valve 17 or 17A or 17B is left open so as to achieve levelling out of water between adjacent modular tanks. A particular gate valve 17 or pair of gate valves 17A and 17B is only closed when it is isolate one modular tank from the other for maintenance purposes.

It will also be appreciated from the foregoing that upper flow conduit assemblies 13 or 13A and 13B are not essential to operation of the invention and it also will be appreciated that adjacent modular tanks do not have to be butted together as shown at 67 in FIG 1 or 68 and 69 in FIG 2 especially if upper flow conduit assemblies 13 or 13A and 13B are omitted.

It will also be appreciated that the invention is specifically adapted for interconnection of corrugated tanks and this is especially achieved by the use of sealing sockets 31 having a peripheral shape 32 that corresponds or is complementary to the corrugated outer wall 46.

It is also pointed out that modular flow tanks 11, 12 and 20, 21 and 22 have a maximum capacity of 2500 litres and more preferably have a capacity of 1500 to 2000 litres. Having such a reduced capacity avoids the need for reinforcement as described above in regard to the prior art.

Claims

7- SCLAIMS S1. A modular tank system for storage of rainwater including a plurality of modular corrugated tanks each having a maximum capacity of 2500 litres having a lower flow conduit assembly connecting each of the corrugated tanks wherein said lower flow conduit assembly is attached to an adjoining 0modular tank by a coupling having a pair of seals formed from elastomeric material and having a peripheral shape that is complementary to corrugations of said adjoining tank wherein one of said seals abuts an internal surface of said adjoining tank and another of said seals abuts an external surface of said adjoining tank. 2. A modular tank system as claimed in claim 1 wherein said coupling also includes a screw threaded fitting which is screw threadedly attached to an adjacent flow circuit of the lower flow conduit assembly and which is also screw threadedly attached to a nut located on the internal surface of said adjoining tank. 3. A modular tank system as claimed in claim 1 or claim 2 wherein said lower flow conduit assembly also incorporates a flow valve for shutting off flow of water through the said flow conduit assembly when required. 4. A modular tank system as claimed in any preceding claim wherein at least one of the modular storage tanks is connected to a storm water conduit which his in flow communication with a gutter or other receptacle for collection of rainwater.